Process for softening fabrics by contacting them with a thiodiglycol derivative

ABSTRACT

A fabric softening composition containing a thiodiglycol derivative corresponding to formula I 
     
         R.sup.1 --O--(C.sub.2 H.sub.4 O).sub.x --(C.sub.2 H.sub.4 --SO.sub.z 
    
      --C 2  H 4  --O) w  --(C 2  H 4  --O) y  --R 2  (I) 
     wherein R 1  and R 2  are the same or different and represent linear or branched alkyl or alkenyl groups containing 6 to 30 carbon atoms or hydrogen, x+y=0 to 20, w is 1 to 5, and z is 1 or 2.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to thiodiglycol derivatives, to their productionby reaction of thiodiglycol with alcohols in the presence of acidiccompounds and subsequent oxidation to the sulfoxide and/or sulfone. Theinvention also relates to the use of the described thiodiglycolderivatives for softening fabrics.

2. Discussion of Related Art

Domestic and institutional fabric softeners contain above all quaternaryammonium compounds, more particularly of the dimethyl distearyl ammoniumchloride type or, more recently, compounds of similar structurecontaining one, two or three fatty acyloxyalkyl groups. On account ofthe increasing significance of stability in storage, viscositycharacteristics and, in particular, biodegradability, above all in thecase of highly concentrated fabric softeners, numerous proposals forreplacing these components by nitrogen-free substitute compounds orcorresponding systems have been published. These proposals encompassboth inorganic components, more particularly inorganic insolublecomponents, such as layer silicate compounds (see, for example, DE-PS 2334 899), and also selected organic components, for example disalts oflong-chain α-sulfofatty acids, and combinations of such systems (see,for example, DE-PS 36 04 039).

Thiodiglycol derivatives, a process for their production and their usefor softening fabrics are already known from German patent applicationDE 39 36 862 A1. However, on account of their limited solubility inwater and their melting points, these compounds can only be made up intodispersions by laborious mixing. The ethoxylates of thiodiglycolderivatives described in German patent application P 40 21 694.2represent an improvement in this regard. They are produced from α-olefinepoxides. Accordingly, the problem addressed by the present inventionwas to provide thiodiglycol derivatives suitable for softening fabricsusing renewable raw materials, another problem addressed by theinvention being to provide a process for the production of thesecompounds which would enable even relatively large quantities to bereadily produced.

DESCRIPTION OF THE INVENTION

Accordingly, the present invention relates to thiodiglycol derivativescorresponding to general formula I:

    R.sup.1 --O--(C.sub.2 H.sub.4 O).sub.x --(C.sub.2 H.sub.4 --SO.sub.z --C.sub.2 H.sub.4 --O).sub.2 --(C.sub.2 H.sub.4 --O).sub.y --R.sup.2 (I)

in which

R¹ and R² may be the same or different and represent linear or branchedalkyl or alkenyl groups containing 6 to 30 carbon atoms or hydrogen,

x+y=0 to 20,

w=1 to 5,

z=1 or 2.

Accordingly, the thiodiglycol derivatives according to the invention areethoxylated and non-ethoxylated bisethers of thiodiglycol sulfoxides orsulfones. Preferred thiodiglycol derivatives of formula I are those inwhich the substituents R¹ and R² derived from fatty alcohols are linearalkyl or alkenyl groups preferably containing 8 to 22 carbon atoms. Eventhough, in principle, R¹ and R² may be derived from fatty alcoholscontaining a uniform number of carbon atoms, it is best for reasons ofcost to use naturally occurring fatty alcohol mixtures for theproduction of the thiodiglycol derivatives. Examples of inexpensivelyavailable fatty alcohol mixtures are coconut oil fatty alcohol, tallowfatty alcohol, palm oil and palm kernel oil fatty alcohol or even peanutoil fatty alcohol. The substituents R¹ and R² may be the same ordifferent. However, since thiodiglycol derivatives containing the samesubstituents R¹ and R² are easier to produce, thiodiglycol derivativesin which R¹ and R² are the same are preferred. Where ethoxylated fattyalcohols are used as the starting material, correspondingly ethoxylatedthiodiglycol derivatives, which are also effective fabric softeners, areobtained. Sulfoxides (z=1) or sulfones (z=2) are obtained, depending onthe extent to which the thiodiglycol derivatives are oxidized.Thiodiglycol derivatives in which z=2, i.e. thiodiglycol sulfones, arepreferred.

The present invention also relates to a process for the production ofthiodiglycol derivatives corresponding to formula I, characterized inthat thiodiglycol is condensed with alcohols corresponding to theformula R¹ --OH and/or R² --OH (where R¹ and R² are as defined above) orethoxylates thereof in a molar ratio of 1:10 to 10:1 in the presence ofacidic compounds at 120° to 200° C. with formation of ether groups, thewater of reaction being removed, and the condensation products areoxidized in known manner to form the sulfoxide and/or sulfone. In onepreferred embodiment of the process according to the invention,thiodiglycol is reacted with alcohol ethoxylates corresponding to theformula R¹ --O--(C₂ H₄ O)_(x) H and/or R² --O--(C₂ H₄ O)_(y) H. Thealcohol ethoxylates used best have relatively low degrees ofethoxylation, i.e. alcohol ethoxylates containing at most 10 moles ofethylene oxide per mole of alcohol are used. The reaction to form ethergroups takes place particularly smoothly when acidic compounds are usedas the catalyst. Accordingly, in another preferred process, acidiccompounds, for example p-toluenesulfonic acid, sulfosuccinic acid orpotassium hydrogen sulfate, are used as the catalyst. Particularlylight-colored products are obtained when the condensation reaction iscarried out in an inert gas atmosphere. Nitrogen is generally used asthe inert gas.

The condensation reaction is followed by the oxidation reaction. In onepreferred embodiment of the oxidation reaction, the oxidation is carriedout with hydrogen peroxide, preferably in the presence of organic acidsor solvents. The oxidation reaction with hydrogen peroxide is preferablycarried out at a temperature in the range from 70° to 100° C.

The present invention also relates to the use of thiodiglycolderivatives corresponding to formula I for softening fabrics of naturaland synthetic fibers and blends thereof. The dryness of the fabric to betreated is not an important factor in the use of the thiodiglycolderivatives in accordance with the invention. Accordingly, the desiredsoftening effect occurs both in wet fabrics and in dry fabrics. Thethiodiglycol derivatives according to the invention are generallyabsorbed onto the corresponding fabric both from aqueous solution and byforced application. The thiodiglycol derivatives according to theinvention are preferably used after a washing or finishing process in anaqueous liquor containing from 0.1 to 1 g/l of the thiodiglycolderivatives corresponding to formula I. The aqueous liquors are bestprepared by diluting aqueous dispersions and/or emulsions containing thethiodiglycol derivatives according to the invention. These dispersionscontain thiodiglycol derivatives in quantities of from about 1 to 50% byweight and best in quantities of 5 to 20% by weight. In one importantembodiment of the invention, the thiodiglycol derivatives are used inadmixture with auxiliaries. Effective auxiliaries are surfactants in abroad sense. Suitable anionic surfactants are, for example, fattyalcohol sulfates and alkyl sulfonate salts, the alkali metal andalkaline earth metal salts and, above all, the sodium and magnesiumsalts having proved to be particularly effective. From the first group,the C₁₆₋₁₈ alcohol sulfate and related compounds may be mentioned as aparticularly suitable mixing component. The second group includes, forexample, α-sulfofatty acid methyl ester sulfonates, disalts ofα-sulfofatty acids and comparable compounds. Suitable nonionicsurfactants are both the conventional ethoxylates and also alkylglycosides. The compounds mentioned may be used as auxiliaries in theproduction of the dispersions/emulsions in the same way as emulsifiersof other classes of compounds, for example glycerides, glycerol partialethers and/or glycerol partial esters which, in addition to one or twofree hydroxyl groups, contain relatively long-chain hydrocarbon radicalsin the ether- or ester-forming functional substituents.

Preservatives, viscosity regulators, acidic compounds, dyes andfragrances may be used as further auxiliaries. The pH value of thedispersions/emulsions may be varied over a broad range, for example overthe range from pH 4 to pH 11 and preferably over the range from pH 5 topH 7.

In addition to the auxiliaries mentioned, the dispersions/emulsions tobe used for softening fabrics may contain other constituents, forexample solvents or stabilizers. The thiodiglycol derivativescorresponding to formula I are preferably used in admixture withsolvents, dispersion aids, emulsifiers and/or stabilizers in quantitiesof 5 to 95% by weight and preferably in quantities of 20 to 70% byweight, based on the active-substance mixture, the thiodiglycolderivatives having to be present in finely dispersed form in order toobtain optimal effects.

Various thiodiglycol derivatives, their production and their use forsoftening fabrics are described in the following Examples which are notintended to limit the invention in any way.

EXAMPLES EXAMPLE 1

This Example describes the preparation of a typical thiodiglycolderivative according to the invention. Other thiodiglycol derivativesaccording to the invention may be similarly prepared using variousalcohols, optionally in various molar ratios with various quantities ofhydrogen peroxide.

3787 g (14 moles) of stearyl alcohol, 855 g (7 moles) of thiodiglycol(Glyecin A, a product of BASF) and 11.4 g of p-toluenesulfonic acidmonohydrate were weighed into a reaction vessel equipped with a stirrerand water separator and heated with stirring to around 170° C. over aperiod of 6 hours during which nitrogen was introduced. The course ofthe reaction was followed from the quantity of water separated. 4400 gof thiodiglycol distearyl ether was obtained in the form of a paleyellow-colored solid.

For oxidation to the sulfone, 1270 g of the thiodiglycol distearyl etherobtained as described above were heated to 80° C. and 433 g of 35%hydrogen peroxide were slowly added over a period of about 60 minutes.After stirring for 4 h at 90° to 98° C., the reaction product wasrepeatedly washed with hot water until no more peroxide could bedetected in the washing water. The pale yellow solid product was thendried in vacuo at 120° C. 1244 g of the sulfone were obtained.

EXAMPLE 2

This Example describes the use and the testing of the thiodiglycolderivatives according to the invention.

Cotton terry swatches were hardened by one wash at 95° C. and fivewashes at 60° C. in a liquor containing 215 g of a phosphate-freedetergent per 3.5 kg of terry swatches. The swatches were not prewashed.This hardened material was given a feel score of 0. Quantities of 60 gof hardened terry swatches were treated for 5 minutes in a Wackermachine with 600 g of an aqueous dispersion containing a mixture of 5%by weight of the sulfone obtained is described above and 4% by weight ofsodium tallow alcohol sulfate (liquor ratio 1:10) in water with ahardness of 16° d. After drying, the softness of the terry swatches wasevaluated by people skilled in the evaluation of softness. A feel scoreof 4 was awarded for a "very soft" feel. Terry swatches which had beentreated with a liquor containing 3 g of the aqueous dispersion describedabove per liter were given a feel score of 3. Terry swatches which hadbeen treated with a liquor having twice the concentration were given afeel score of 4.

Comparable results are obtained when n-octyl alcohol or a mixture ofn-octyl alcohol with stearyl alcohol or behenyl alcohol was used insteadof stearyl alcohol for forming the ether groups. An equally good resultwas obtained with a product where the alcohol was used in less than andmore than equivalent quantity for forming the ether groups. The feelscores of the test fabrics thus treated were in the range from 3.0 to3.4 for an in-use concentration of 3 g per liter.

EXAMPLE 3

7.5 g of a 30% solution of potassium hydroxide in methanol were added to900 g of a mixture of cetyl alcohol and stearyl alcohol (1:1), followedby heating to 80° C. in an autoclave. At this temperature, the traces ofmethanol present were removed by evacuation and purging with nitrogen atotal of five times. After the reaction temperature had been increasedto 140° C., a total of 154 g of ethylene oxide was added in portions insuch a way that the pressure in the reactor did not exceed 5.10⁵ Pa. Oncompletion of the reaction, the reaction mixture was cooled to around90° C. and was evacuated for 15 minutes to remove the traces of ethyleneoxide still present. A colorless solid with an OH value of 185 wasobtained.

Yield: 1061 g of fatty alcohol ethoxylate.

760 g of fatty alcohol ethoxylate, 153 g of thiodiglycol and 15 g ofp-toluenesulfonic acid monohydrate were reacted as in Example 1 (4.5hours, 160°-180° C., quantity of water separated 46 ml).

The reaction product was oxidized with 255 g of 35% hydrogen peroxide asin Example 1. Yield: 838 g, OH value: 24, acid value: 1.4.

EXAMPLE 4

1061 g of 2-hexyl decanol, 244 g of thiodiglycol and 3.6 g ofp-toluenesulfonic acid monohydrate were reacted as in Example 1 (5hours, 160°-170° C., quantity of water separated 66 ml).

The reaction product was oxidized with 393 g of 35% hydrogen peroxide asin Example 1. Yield: 1235 g, OH value: 54, acid value: 0.8.

EXAMPLE 5

1117 g of oleyl alcohol (iodine value 90-95), 244 g of thiodiglycol and3.6 g of p-toluenesulfonic acid monohydrate were reacted as in Example 1(5.5 hours, 160°-170° C., quantity of water separated 65 ml).

The reaction product was oxidized with 393 g of 35% hydrogen peroxide asin Example 1. Yield: 1222 g, OH value: 54, acid value: 0.2, iodinevalue: 76.

EXAMPLE 6

866 g of a technical alcohol mixture (5% C₈, 5% C₁₀, 50% C₁₂, 20% C₁₄,10% C₁₆, 8% C₁₈) , 269 g of thiodiglycol and 4.0 g of p-toluenesulfonicacid monohydrate were reacted as in Example 1 (6 hours, 160°-170° C.,quantity of water separated 70 ml).

The reaction product was oxidized with 499 g of 35% hydrogen peroxide asin Example 1. OH value: 55, acid value: 0.6.

EXAMPLE 7

886.9 g of 1-hexadecene oxide and 315.3 g of thiodiglycol+2 EO(thiodiglycol reacted with 2 moles of ethylene oxide) were introducedinto a reaction vessel together with 7.8 g of a 50% potassium hydroxidesolution and traces of water present were removed by heating in vacuo to100° C. The slightly exothermically reacting mixture was then heatedunder nitrogen to around 160° to 170° C. To monitor the reaction, theepoxide oxygen content of the reaction mixture was determined at regularintervals, an epoxide oxygen content of less than 0.3% being reachedafter a reaction time of 3 to 6 hours, indicating that the reaction wasover. After cooling, the product was neutralized with an equivalentquantity of 90% lactic acid.

1100 g of the reaction product prepared as described above were heatedto 80° C. and 153 g of 70% hydrogen peroxide were slowly added over aperiod of 60 minutes. During the subsequent reaction, the temperaturewas kept below 90° C. by cooling. For the after-reaction, the productwas heated for 4.5 hours at 90° C. and then washed with hot water untilthe peroxide test in the washing water produced a negative result. Thelight yellow solid sulfone was then dried in vacuo at 120° C.

OH value: 149, acid value: 0.9.

EXAMPLE 8

611 g (5 moles) of thiodiglycol and 3.1 g of p-toluenesulfonic acidmonohydrate were introduced into a reaction vessel equipped with astirrer and water separator and heated to 140°-180° C. while nitrogenwas passed through (3.5 h). The course of the condensation reaction wasfollowed from the quantity of water removed (quantity of water removed45 ml+30 ml of thioxane). After addition of 1353 g (4.5 moles) ofstearyl alcohol, the reaction mixture was heated for another 3 h at 170°C. (quantity of water 80 ml).

The reaction product was oxidized with 895 g of 35% hydrogen peroxide asin Example 1. Yield: 1627 g, OH value: 16, acid value: 0.8.

EXAMPLE 9

651 g of octanol, 306 g of thiodiglycol and 4.6 g of p-toluenesulfonicacid monohydrate were reacted as in Example 1 (6 h, 160°-180° C.,quantity of water separated 80 ml) and oxidized with 495 g of 35%hydrogen peroxide. Yield: 758 g, OH value: 36, acid value: 0.6.

We claim:
 1. The process of softening fabrics comprising contacting saidfabrics with a fabric softening composition comprising a thiodiglycolderivative corresponding to formula I

    R.sup.1 --O--(C.sub.2 H.sub.4 O).sub.x --(C.sub.2 H.sub.4 --SO.sub.z --C.sub.2 H.sub.4 --O).sub.w --(C.sub.2 H.sub.4 --O).sub.y --R.sup.2 (I)

wherein R¹ and R² are the same or different and represent linear orbranched alkyl or alkenyl groups containing 6 to 30 carbon atoms orhydrogen, x+y equals 0 to 20, w is 1 to 5, and z is 1 or
 2. 2. A processas in claim 1 wherein R¹ and R² are linear alkyl or alkenyl groupscontaining from 8 to 22 carbon atoms.
 3. A process as in claim 2 whereinR¹ and R² are the same.
 4. A process as in claim 1 wherein z is
 2. 5. Aprocess as in claim 1 wherein said thiodiglycol derivative is present insaid composition in an amount of from about 1 to 50% by weight, based onthe weight of said composition.
 6. A process as in claim 1 wherein saidthiodiglycol derivative is present in said composition in an amount offrom about 5 to 20% by weight, based on the weight of said composition.7. A process as in claim 1 wherein said composition further contains anauxiliary selected from the group consisting of anionic surfactants,nonionic surfactants, preservatives, viscosity regulators, solvents,dispersion aids, emulsifiers and stabilizers.
 8. A process as in claim 1comprising contacting said fabrics with an aqueous liquor containing 0.1to 1 gram/liter of said thiodiglycol derivative.